Amoxicillan, bloody stool, and anemia--is there a link?

My 3-year old had bulls eye rash so went in to dr. to get checked.  They took blood sample and did lyme's titer and complete blood count.  The lyme's test came back positive and she's on amoxicillan (1 tsp. 3x/day)for a month.  Also, she is said to have "slight anemia" and she will be starting on iron supplements today.

She has been on Amoxicillan for 11 days.  The first bottle of the Amoxicillan was mixed incorrectly (the consistency of silly putty )at the pharmacy so she was getting a stronger dose (a 10-day dose lasted 4 days).  The pharmacy gave me a new batch free of charge but wouldn't admit any error on their part.  

Yesterday she has a bowel movement (normal consistency, no straining, no visible injury to her bottom) and passed blood.  Blood was on the surface of the stool.  I could see droplets of blood in the water and some dripped down her leg.  Her bowel movements are regular and this is the first time any blood was noticed.  (She's a fearful child by nature and was a little freaked out by the blood so I'm sure she would have said something if it had happened before)

My doctor is on vacation for the week and her substitute wants me to "wait and see what happens".  

I want to know it there's possibly any connections to the overdose of amoxicillan, the anemia and the bloody stool.  How much blood should a 3-year-old pass with a bowel movement before it's a cause for follow-up by a dr.?

[Kevin Pho, MD]

I am not aware of a connection between the amoxicillin to the anemia and bloody stool.

Blood in the stool is never normal.  It may be caused by benign causes such as too much straining or hard stools.  If it is the cause of the anemia, then one can consider an endoscopy for an evaluation.  There is no "safe" amount of blood loss.

If there are no signs of severe blood loss (i.e. lethargy, dizziness etc.), I would suggest bringing your child in to see the physician.  Of course, if there are any concerning symptoms, then an ER evaluation would be apporpriate.  

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Kevin, M.D.
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